Networks are used to distribute information among computer systems by sending the information in segments such as packets. A packet typically includes a “header” that directs the packet through the network to a destination, and a “payload” that stores a segment of information being sent through the network. At particular locations in the network, the packet header is accessed to identify the packet's destination and determine the path in the network to send the packet. To determine the path, data in the packet's header is compared to data stored at the network location for a potential match. By matching the header data and the locally stored data, an appropriate path is identified and the packet is sent over the path for delivery to its destination.
In general, an in-line device may refer to a specialized server or hardware device which does more than just forward packets as do hubs, switches and standard routers. As such it may require higher processing power per packet and may be capable of handling less than the traffic being handled by the simpler network devices. In-line devices may be used in a variety of different applications such as compression, intrusion prevention, application layer inspection, etc. Due to the relatively high central processing unit (CPU) requirements per packet, these devices may be susceptible to extremely high traffic flows, which may create both intentional and incidental denial of service (DoS) attacks on these devices. Some network devices may employ a number of different techniques in order to control and prioritize traffic.
Although the following Detailed Description will proceed with reference being made to illustrative embodiments, many alternatives, modifications, and variations thereof will be apparent to those skilled in the art.